Cancelled shows

When the tour was announced earlier this year, Mortimer said: "Playing in front of a living audience is where it all began for us."

He added: "I will ensure that Vic arrives at all dates smartly dressed and unarmed. I promise not to mention football, JLS or apricots during the performances.

"Should you choose to attend, be warned - I will be not be wearing a toupee."

Image caption
Mortimer took part in Let's Play Darts for Comic Relief earlier this year

Fellow comedians and broadcasters have wished Mortimer well on Twitter, including Jack Dee, Charlie Higson and Sherlock actor and writer Mark Gatiss who said: "All love and luck @RealBobMortimer for a speedy recovery, pet."

Absolute Radio presenter Christian O'Connell said: "Get well soon @RealBobMortimer. The man's a true gent and been making me laugh for years."

Pointless star Richard Osman wrote: "The loveliest, funniest man you could ever hope to meet. Get well soon."

What is a triple heart bypass?

The heart is covered in blood vessels that feed it with oxygen and nutrients.

But fatty deposits - which are more common in smokers or overweight people - can clog up these arteries.

A heart bypass - official known as a coronary artery bypass graft - uses blood vessels from other parts of the body to rewire the heart's blood supply.

Arteries and veins from the the arm, chest and leg are used to bypass any blockages.

Some patients have only a single bypass, but it is more common for two, three (a triple heart bypass) or four grafts to be needed.

It is a common operation with around 20,000 taking place in England alone every year.